Cooked Vanilla Frosting (and my favorite chocolate cake)

This is a classic recipe for a vanilla frosting that is made with (of all things) a roux of cooked milk and flour. When added to whipped butter and granulated sugar, the frosting whips up to resemble a silky whipped cream frosting. It's one of the best cake icings I've ever made, and it couldn't be easier! I've decided to include the recipe for my favorite extra-moist chocolate cake. Together, this makes an impressive cake that will disappear fast!